Trough for use in alloying metals



Patented Aug. 22, 1950 I 2,519,593 TROUGH FOR USE IN ALLOYING METALS Charles M. Offenhauer, Niagara Falls, N. Y., as-

signor, by mesne assignments, to Union Carbide and Carbon Corporation, a. corporation of New York Application August 12, 1948, Serial No. 43,832

1 Claim. (Cl. 266-34) The invention relates to an apparatus for incorporating alloying elements into molten metal.

The addition of alloying elements to molten metal to effect changes in its composition and properties is as old as the art of metallurgy. During this long history numerous readily soluble alloying materials and ferro-alloys have been developed which may be conveniently incorporated into molten metal by conventional means. Despite these developments, certain types of alloying materials are introduced into molten metal only with great difficulty. Among such alloying materials are metal fines, which tend to become trapped in slag; light weight addition materials, which tend to'float upon the surface of molten metal and become badly oxidized; and materials having melting temperatures near or well above the temperature of the molten metal into which they are to be incorporated.

It is a primary object of the present invention to provide an apparatus which is simple, eflicient and accurate for introducing alloying elements into molten metal. Another object is to provide an apparatus whereby metal fines, light weight metals, and alloys may be eflectively incorporated into molten metal without oxidation or danger of slag entrapment. A still further object is to provide an apparatus whereby controlled amounts of alloying elements may be introduced into molten metal in such a way that homogeneity between the added material and the molten bath is assured. Other objects of the invention will become apparent as this description proceeds.

In the drawing:

Figure 1 is an elevational view, parts being 1 Broadly, the invention comprises placing alloy- ,5

ing materials to be incorporated into molten metal on the pouring trough from a meltin furnace and utilizing the mechanical motion of the metal flowing through said trough to assist in the solution of the alloying materials. By flowing the metal to be alloyed over the alloying materials in added, or deoxidation treatments may be performed in the ladle by conventional means in conjunction with the method of the invention.

Referring to the drawing, particularly to Figure 1, a typical arrangement suitable for introducing various alloying materials into molten metal is shown. A pouring trough ID from any source of molten metal is lined in the customary manner by refractory lining l2. Over the refractory lining is placed a paste of the alloyipwimlg to be introduced into the nfolt'fi metal It as it passes through the trough into ladle It. The arrangement of the pouring spout, refractory lining, and alloying overlay is more clearly seen by reference to Figure 2.

Any desired binding material may be used in preparing the alloy paste l4. Sodium silicat is an example of a suitable bindlll g medium, The arrangement shown in Figumm'ffile suitable for the introduction of alloying materials generally, is particularly suitable for the introduction of fines and light metals. By this arrangement the fines or light metals are securely held in place until dissolved by the molten metal passing through the trough. As is apparent from the drawing, the alloying material is at all times throughout the alloying operation entirely covered by the flowing molten metal and accordingly protected from oxidation. Further, since pouring troughs are not heated prior to use no oxidation occurs before the alloying operation starts. Thus by the apparatus of the invention the alloying material is uniformly introduced into the molten metal free from undesirable oxides.

The effectiveness of the apparatus of the invention will be further shown by examples wherein alloying materials were introduced into steel. In one example, a heat of SAE 1020 steel was prepared in an induction furnace. A compact prepared from comminuted high-carbon ferrochromium using 6.7% 22 Be. s'odiu'm sfiicate as a binder was cemented into the pouring trough of the furnace; the amount of high-carbon ferrochromium in the compact being suficient to introduce 1% chromium into the steel. Upon tapping the furnace, the flowing metal in the pouring trough completely dissolved the high-carbon ierrochromium compact.

The apparatus of the invention is also highly adapted for use with diflicultly soluble alloys. In a run conducted in .the same manner as the above-described example, 0.06% nitrogen was introduced into SAE 1020 steel from an alloying addition in the pouring trough of comminuted ierrosilico nitride (30% nitrogen) with sodium carBonate as bifi'd'w' The introduction of alloying materials into molten metals by means of the apparatus of the invention may also be efiected with alloying materials in uncompacted, granular form. Figure 3 shows in longitudinal, cross-section a form of pouring trough suitable for use with uncompacted, granular materials. In the figure, a conventional pouring trough 20 is lined with a refractory material 22, the lining being provided with one or more cavities or pockets which are filled with granulated alloying material 24 to be introduced into the molten metal 26 as it passes through the pouring trough 20. This modification of the apparatus of the invention is particularly effective with alloying additions having a specific gravity approaching or greater than that of the flowin metal. For some purposes it may be desirable when using this modification of the apparatus of the invention to retain the alloying material in the bottom or the pouring trough in metal trays, cans or other similar containers which would dissolve along with the alloying material.

Modifications, other than those specifically set forth in the drawings, are within the intended scope of the invention. For example, the invention contemplates such modifications as lengthening the pouring trough for use with large alloy additions, or altering the general shape of the 30 4 pouring trough to afford a larger surface of contact with the flowing metal.

What is claimed is:

A casting device for incorporating alloying materials into molten metal comprising, in combination, a pouring trough adapted to receive a retractory lining; a refractory lining in said trough so shaped as to enable the passage of a stream of flowing metal therein; and, in the bottom of said refractory lining and afiixed thereto so as to resist displacement, an alloy retaining means in the form of metal trays and cans.

CHARLES M. OFFENHAUER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 543,115 Uehling July 23, 1895 620,810 Hadfield Feb. 28, 1899 1,235,872 Baldwin Aug. '7, 1917 1,350,972 Irvin et al Aug. 24, 1920 1,633,992 Madden June 28, 1927 FOREIGN PATENTS Number Country Date 2,252 Great Britain of 1878 159,809 Great Britain Mar. 10, 1921 

